“Earmarks,” also known as pork-barrel spending, are considered a “gateway drug” to corruption and bigger government in Washington. They got that well-deserved title because there’s a history of both Republicans and Democrats using earmarks as a currency to buy votes for all sorts of bad policies. Sometimes, members of Congress have actually taken bribes in exchange for obtaining earmarks. The system was abused so badly that Americans shamed both parties into passing a temporary ban on the practice.

Thankfully, there are very few Republicans left who still support earmarks. Regrettably, one of the remaining few is 35-year Indiana senator Richard Lugar. He continues to stand in favor of earmarks to this day. Recently, Lugar was one of only thirteen Republicans to join Senate Democratic leader Harry Reid in voting against a permanent ban on earmarks.

That was the final straw for the Club for Growth PAC, which has now endorsed Lugar’s conservative challenger, Indiana state treasurer Richard Mourdock.